Syrian Kurdish fighters launched Sunday an offensive on the Islamic State militants to seize control of the strategic IS-held town Tal Abyad on the Turkish border, Kurdish officials and an activist group said. Taking Tal Abyad, some 80 kilometres (50 miles) north of the IS stronghold of Raqqa, would deprive the group of a direct route to bring in new foreign militants or supplies. The Kurdish advance, coming under the cover of intense U.S.-led coalition airstrikes in the area, also would link their two fronts and put even more pressure on Raqqa as Iraqi forces struggle to contain the group in their country. Meanwhile, hundreds of Syrian civilians trying to flee the offensive pressed against the barbed wire fences separating the town from Turkey, as masked militants likely belonging to the Islamic State group could be seen while Turkish soldiers watched from the other side.